Strange Regex/Invoke issue

this.Invoke(ReceivedWhisper, match.Groups["SenderName"].Value, match.Groups["Message"].Value);

Ok, so when this gets called it points to 'Value' of match.Groups["SenderName"].Value, and says "Object reference not set to an instance of an object." even though when I mouse over that .Value part, it has a value in it. Do any of you know why it is saying an object with a value is not set to an instance of an object?